As an example, the regeneration circuit in accordance with the invention is applicable in the demodulators of teletext broadcast system such as the one described in U.S. Pat. No. 4,058,830 and FR-A-2,313,825, this system being known and used in France under the name DIDON. In the data broadcast systems, the data packets carried by the television lines are positioned in these lines at a fixed time lapse after the line synchronization signal. In over the air transmissions, the signal to noise ratio often fluctuates such that the line synchronization signal is not received. The television receiver circuits are such that, under these conditions, they restore an acceptable picture because the analog signal varies only slightly from one line to the next and because interlaced sweeping is used. However, in data transmission, there is no correlation between the data streams on two different lines. We must therefore have, at each line a synchronization signal.